Baseboard radiation has become popular for heating both residential and commercial buildings. Unlike the traditional full size radiators, baseboard convectors are unobtrusive, blend in with the room decor and do not interfere with the placement of furniture in a room.
Another attractive feature of baseboard convectors is its simplicity of installation in many applications. However, while baseboard heating units are easily installed on for example, the ground floor of a building which has a basement providing ready access to pipes, buildings without basements, constructed on solid concrete foundations (sometimes referred to as "slabs"), present serious installation problems. When a baseboard heating system has to cross a doorway in a building with a basement, the circulating pipes are generally run through the floor at one side of the door under the floor beneath the doorway and then up through the floor at the other side of the doorway. In buildings without basements and where the baseboard radiation being installed is to bridge a doorway, a trench must be cut in the concrete along the threshold, the connecting pipe laid in the trench and the remainder of the trench filled with new concrete. This process is difficult, time consuming and expensive. Because of this serious drawback, baseboard heating is not often installed in buildings on slabs.
In buildings with concrete floors, the original circulating hot water or steam pipes for heating are embedded in the concrete flooring as the floors are poured. Repair of this type of heating system is costly because concrete floor must be broken up to reach the embedded pipes. Replacement of this type of heating system with baseboard convectors, an otherwise attractive alternative to costly repairs of the concrete embedded pipes, has heretofore been impracticable in many instances because of the expense and difficultly in extending connecting pipes across doorway thresholds.